A real record on crime: Serving under Mayor Rudy Giuliani, Joe Lhota learned what works.William Farrington

City Council Speaker Christine Quinn’s plan to impose an inspector general on the NYPD — that is, to subordinate one of the world’s most professional urban police agencies to the currents of everyday ethnic and cultural politics — drew some useful criticism yesterday from Joe Lhota, her fellow mayoral candidate.

“Reckless and dangerous” was how Lhota described the scheme — though craven and opportunistic would also have fit.

Lhota, a Republican, was deputy mayor to Rudy Giuliani. Regarding public safety, he’s been there.

Quinn, the conventional-wisdom favorite among the Democrats, says her “No. 1 priority is to keep New York City the safest big city in the country.”

So, on the one hand, there is a solid record. On the other, there are . . . words.

But as this particular debate proceeds, it will become clear enough where the credibility resides.

Essentially, it’s about one of the NYPD’s most effective anti-crime tactics — what’s called “stop and frisk.” Cops patrol high-crime areas; when observation and experience suggest to them that an individual is behaving suspiciously — possibly carrying a gun, for example — they ask a few questions and, in some cases, perform a search.

To good, if controversial, effect.

What’s beyond doubt is this: Cities that employ intrusive tactics like “stop-and-frisk” — New York and LA, for example — are relatively safe. Cities that don’t — e.g. Chicago, Detroit and Philadelphia — are war zones.

New York used to be a war zone, too. But that was a long time ago — itself a critical, if generally understated, element in the debate.

When people are threatened, as 20 years ago they surely were, they embrace aggressive policing. But when the danger seems to have passed, other concerns come to dominate the discussion.

Among them are understandable, if misplaced, ethnic, racial and cultural sensitivities — which then are absorbed into the agendas of New York’s radical activists, its hyperkinetic civil-liberties bar and some strategically placed (and scandalously accommodating) judges.

Central to their argument is this: The overwhelming majority of those caught up in the stop-and-frisk net are black or Hispanic. Disparate impact, anyone?

Well, no: The stops almost exactly mirror the ethnicities of both the perpetrators and the victims of crime. This all too rarely makes it into the discussion — even though the ratios on their face disprove allegations of selective law enforcement or unreasonable profiling.

Nor, again, can this fact fairly be disputed: The tactic works.

Alas, it’s probably doomed.

Quinn’s inspector-general proposal is ostensibly a compromise, and, in context, it may well be. But who’s to doubt that she seeks to saddle the NYPD with what amounts to a political commissar? The net effect of this would be to dilute the authority of the mayorally appointed police commissioner, to diffuse operational responsibility within the department and — critically — to undercut command accountability.

This may be intentional. Or not. Either way, it displays a disturbing lack of understanding of the essential element in the Rudy Guiliani-Mike Bloomberg anti-crime strategy: Individual precinct commanders are held personally to account for the successes — and failures — of subordinates. The subordinates thoroughly understand this; they sometimes resent it, but they perform.

Do away with accountability — or even mildly compromise it — and the NYPD is headed back to the days when “police work” mostly comprised taking robbery reports and toe-tagging bodies.

Indeed, as Lhota observed yesterday, murder has continued its dramatic two-decade decline over the past couple of years — even as small but significant increases in other major crime, including rape and assault, occurred.

“This proves just how fragile our successes are,” he said, “and how vigilant we must be to keep improving upon them.”

There are no guarantees, in other words. Well, maybe one guarantee: In politics, principles are supremely fungible. Quinn last week jettisoned her opposition to mandatory paid sick leave like an extra anchor — never mind that the bill she now backs will cost jobs and, eventually, depress the city’s economy.

And never mind that she knows it. She has said as much.

Just as she also knows that politicizing the Police Department to no legitimate purpose serves only criminals and their apologists.

True enough, Giuliani himself was sympathetic to the notion of an IG, back in 1993. But a lot has happened since then — and, anyway, if Quinn really thought the office had some utility, she would have said so long before now. She has been council speaker since 2006, after all.

No, Christine Quinn chooses to follow, not to lead.

This is not an attractive quality in a mayoral candidate. Nor a mayor, for that matter.

“I call upon Speaker Quinn to withdraw her support for this [inspector-general] bill,” said Lhota yesterday morning.